Syntax and semantics of a subset of the path notation are introduced. Then a property of path programs called adequacy is defined; roughly, programs are adequate if there is no partial deadlock. Fianlly, two results are presented concerning adequacy. The first result solves the adequacy problem for a certain subclass of programs, and the second result characterises the problem in terms of PT-nets for another subclass. An overview of the results on adequacy which have been obtained so far is also given. Even so, this is intended to serve as an introductory text.